Problem: Solve for $q$ : $q + 5 = 25$
Explanation: Subtract $5$ from both sides: $ \begin{eqnarray} \\ q + 5 &=& 25 \\ \\ {-5} && {-5} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{5 + q} &\hphantom{=}& \hphantom{25} \\ q &=& 25 {- 5} \\ \end{eqnarray} $ Simplify. $ q = 20$